This invention is related to surgical drains for use in draining fluid that may collect within a surgical wound, and more particularly, to a surgical drain apparatus and method for draining fluid from a wound while preventing contaminants from entering the wound and while preventing substantial leakage of drained fluid.
It is the present medical practice to place a drain in any surgical wound where contamination, trauma, excessive bleeding, or other factors may lead to the accumulation of serous fluid, blood, or pus within the wound. The purpose of surgical drains is to prevent the accumulation of surgical fluids and the toxic substances of degradation by allowing the fluids to exit the body.
There are principally two categories of surgical drains, passive drains and active drains. Both types of drains generally include an elongated drain member or tube and a fluid receptacle adapted to be connected to one end of the drain member for receiving the drained fluids. A drain member generally includes a fluid flow passage extending the length of the member for providing a path through which fluids exit the patient's body. A drain member also includes a fluid intake portion that is adapted to be inserted into the patient's body through a drain wound or incision and positioned inside the patient's body for receiving fluids that are likely to develop.
Typically, both categories of prior drain members were exited through a separate small drain wound made specifically for exiting the drain. The additional drain wound was used primarily because the wound could be sized for a tight fit with the drain member so as to reduce leakage between the wound and the drain member. The separate drain wound also provided an exit for the drain member without interfering with the healing of the primary surgical wound or incision.
Passive surgical drains generally include a drain member comprised of a thin walled tube or strip made of a suitable material such as rubber or flexible plastic. A passive drain simply prevents the wound edges or drain site incision edges from becoming adherent and provides a channel through which fluid may flow into or out of the wound.
Active surgical drains in addition to providing a channel through which fluids may exit the patient's body also include some means of applying negative pressure or suction to the drain member. The negative pressure or suction enhances the flow of fluids from the wound and also helps to dislodge small particles that may occasionally block the drain member flow passage. The negative pressure is usually applied with a spring activated bellows incorporated into the fluid receptacle. Some of these negative pressure receptacles also have anti-reflux or one-way valves to prevent fluids in the receptacle from flowing back into the wound.
There are also some differences in the drain members used in active as opposed to passive drain systems. By contrast to the thin walled drain members used in passive drains, the drain member used in an active drain system must be relatively thick-walled to prevent the collapse of the flow passage under the applied negative pressure. Also, the intake portion of a drain member used in an active drain system often includes a number of small slits or holes along its length that enable fluids to enter the drain from a large area within the wound.
Although the intake portion of the drain members have been designed in a variety of transverse cross-sectional shapes or configurations, they are generally either round or rectangular. The rectangular-shaped drains are often described as being flat drains with the implication that some maximum amount of surface area for large flow can be achieved without distorting the tissues or organs that the drain member may pass. Also, regardless of the shape of the intake or inter-wound portion of the drain member, prior drain members have all included a generally round portion that is positioned at the host-prosthesis interface.
There are a number of problems associated with prior surgical drains. One such problem is that prior drain systems allowed contaminants to enter the wound either by back flow into the wound through the drain member or by leakage between the drain member and the drain wound edges. Leakage of fluids out of the wound between the drain member and the drain wound edges is another problem heretofore encountered in the use of surgical drains known in the art.
Leakage between the drain member and the drain wound occurs primarily because of gaps between the drain members previously used and the edges of the drain wound. In order to produce a lasting seal, the wound edges must be made to conform to the shape of the drain member with substantially no gaps at any point around the member. However, the drain wound made with a trochar or awl is always generally elliptical in shape whereas the portion of the prior drain members that traverses the wound was generally round in transverse cross-sectional shape. Although the rounded drain members or tubes could be passed via a small incision or wound through the skin and subcutaneous tissue in a very tight relationship, any seal obtained was temporary at best because of the pressure necrosis of the intervening tube through the wound. Also, even where the drain member fit very tightly through its own separate drain incision, a draining sinus tract usually developed over time that allowed the free egress of drained fluids from the wound and the ingress of skin contaminants and other bodily secretions from outside the wound.
Contaminants enter the drain wound through the drain tube itself not only in passive drains where there is no means to draw fluid to the receptacle, but also in prior active drains when negative pressure was removed from the drain tube such as when the receptacle was changed or drained. When a drain receptacle was drained or changed, it was generally disconnected from the drain member which stayed in place extending through the wound and into the patient's body. At disconnection, contaminants were sucked into the drain member flow passage through the disconnected open end of the drain member. The contaminants once in the drain member, could even flow into the wound if suction was not re-established fairly quickly to draw the contaminants out of the drain member and into the receptacle.
Another problem arose in the prior drains where the inter-wound or intake portion of the drain was rectangular with the remainder of the drain member having a round shape. Such drains were generally not integrally formed due to the two dissimilar shaped sections and there was generally a seam remaining where the two sections were joined. Not only was the junction of the two dissimilar drain member sections always a site of possible failure, but also the seam at the junction of the two sections and the change in shape itself caused substantial pain to the patient when the drain was pulled through the body tissues and out through the drain incision as the drain was removed.